Optical information recording medium and manufacturing method and recording/reproducing method for the same

Abstract

An optical information recording medium of the present invention includes at least one information layer. The information layer includes a first protective film, a first interface film, a recording film having the optical characteristics that are changed reversibly by laser beam irradiation, a second interface film, a second protective film, and a reflective film, present in the indicated order from the laser beam incident side. The first interface film includes an oxide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si. The second interface film includes carbon or a carbide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si.

1. An optical information recording medium comprising at least one information layer, the information layer comprising:
 a first protective film; 
 a first interface film; 
 a recording film having optical characteristics that are changed reversibly by laser beam irradiation; 
 a second interface film; 
 a second protective film; and 
 a reflective film, present in the indicated order from a laser beam incident side, 
 wherein the second interface film includes carbon or a carbide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si, and 
 the first interface film includes a mixture of an oxide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, and Ta and an oxide of at least one element selected from the group consisting of Cr, Mo, and W. 
 
   
   
     2. An optical information recording medium comprising a multilayer structure comprising a first information layer to a nth information layer that are stacked in order from the laser beam incident side (n is a natural number not less than 2), at least one of the first information layer to the nth information layer comprising:
 a first protective film; 
 a first interface film; 
 a recording film having optical characteristics that are changed reversibly by laser beam irradiation; 
 a second interface film; 
 a second protective film; and 
 a reflective film, present in the indicated order from a laser beam incident side, 
 wherein the first interface film includes an oxide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si, and 
 the second interface film includes carbon or a carbide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si. 
 
   
   
     3. The optical information recording medium according to  claim 2 , wherein at least the nth information layer comprises the first protective film, the first interface film, the recording film, the second interface film, the second protective film, and the reflective film, present in the indicated order from the laser beam incident side,
 the first interface, film includes an oxide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W,and Si, and 
 the second interface film includes carbon or a carbide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si. 
 
   
   
     4. The optical information recording medium according to  claim 2 , wherein the first interface film includes a mixture of an oxide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, and Ta and an oxide of at least one element selected from the group consisting of Cr, Mo, and W. 
   
   
     5. The optical information recording medium according to  claim 1 , wherein the mixture includes an oxide of at least one element selected from the group consisting of Cr, Mo, and W in an amount of not less than 5 mol % and not more than 80 mol %. 
   
   
     6. The optical information recording medium according to  claim 4 , wherein the mixture includes an oxide of at least one element selected from the group consisting of Cr, Mo, and W in an amount of not less than 5 mol % and not more than 80 mol %. 
   
   
     7. The optical information recording medium according to  claim 1 , wherein the mixture further includes an Si oxide. 
   
   
     8. The optical information recording medium according to  claim 4 , wherein the mixture further includes an Si oxide. 
   
   
     9. The optical information recording medium according to  claim 7 , wherein the mixture includes the Si oxide in an amount of not less than 5 mol % and not more than 60 mol %. 
   
   
     10. The optical information recording medium according to  claim 8 , wherein the mixture includes the Si oxide in an amount of not less than 5 mol % and not more than 60 mol %. 
   
   
     11. An optical information recording medium comprising a multilayer structure comprising a first information layer to a nth information layer that are stacked in order from a laser beam incident side (n is a natural number not less than 2), at least one of the first information layer to the nth information layer comprising:
 a first protective film; 
 a recording film having optical characteristics that are changed reversibly by laser beam irradiation; 
 an interface film; 
 a second protective film; and 
 a reflective film, present in the indicated order from the laser beam incident side, 
 wherein the interface film includes a carbide of at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, and Si and has a thickness of not less than 0.3 nm and up to 1 nm. 
 
   
   
     12. The optical information recording medium according to  claim 11 , wherein the medium has a multilayer structure comprising a first information layer to a nth information layer that are stacked in order from the laser beam incident side (n is a natural number not less than 2), and at least one of the first information layer to the nth information layer corresponds to the information layer as recited in  claim 11 . 
   
   
     13. The optical information recording medium according to  claim 11 , wherein at least the nth information layer comprises the first protective film, the recording film, the interface film, the second protective film, and the reflective film, present in the indicated order from the laser beam incident side. 
   
   
     14. The optical information recording medium according to  claim 1 , wherein the reflective film comprises a first film of Al or Al alloy and a second film of Ag alloy, and the first film and the second film are stacked in the indicated order from the laser beam incident side. 
   
   
     15. The optical information recording medium according to  claim 11 , wherein the reflective film comprises a first film of Al or Al alloy and a second film of Ag alloy, and the first film and the second film are stacked in the indicated order from the laser beam incident side. 
   
   
     16. The optical information recording medium according to  claim 1 , wherein the recording film is at least one selected from the group consisting of a Ge—Sb—Te alloy film, a Ge—Sn—Sb—Te alloy film, a Ag—In—Sb—Te alloy film, an In—Ge—Sb—Te alloy film, and a Ag—In—Ge—Sb—Te alloy film. 
   
   
     17. The optical information recording medium according to  claim 11 , wherein the recording film is at least one selected from the group consisting of a Ge—Sb—Te alloy film, a Ge—Sn—Sb—Te alloy film, a Ag—In—Sb—Te alloy film, an In—Ge—Sb—Te alloy film, and a Ag—Tn—Ge—Sb—Te alloy film. 
   
   
     18. A method for recording/reproducing information with respect to an optical information recording medium comprising:
 recording/reproducing information with respect to the optical information recording medium according to  claim 1  or  11 , 
 wherein the information is recorded/reproduced by an optical system having a wavelength of not more than 450 nm and a numerical aperture of not less than 0.8.